Extract treatment of HIV-1 particles and target cells, but not of target cells alone, inhibits HIV-1 replication. (A) Particle and cell treatment. HIV-1NL4-3 stocks were exposed to aqueous extracts at concentrations from 0.001 to 0.3% (lemon balm), 0.006 to 3% (peppermint), or 0.006 to 1% (sage), solvent only, or efavirenz for 1 h, and then added to Sup-T1 T-cells. (B) Cell treatment. Alternatively, Sup-T1 cells were directly exposed to aqueous extracts, solvent, or overnight. efavirenz for 1 h. Subsequently, cells were washed and challenged with HIV-1NL4-3 Analysis of HIV-1 replication was performed as described in the legend to Fig. 1. Shown are arithmetic means ± SD relative to untreated controls (set to 100%) from one experiment. The inscription for the x-axis of (B) applies also to the x-axis of (A).